Local Cell Membrane Deformations due to Receptor-Ligand Bonding as Seen by Reflection Microscopy

Galle, Joerg; Reibiger, Ina; Westermann, Martin; Richter, Walter; Löffler, Sabine

doi:10.1080/15419060214523

Cited by 5 publications

(6 citation statements)

References 42 publications

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“…This work identifies the interaction collagen XXIII and integrin ␣ 2 ␤ 1 by solid phase and surface plasmon resonance spectroscopy and describes their co-localization on the surface of basal keratinocytes in mouse skin at the microscopic level. In addition, we show at the ultrastructural level that collagen XXIII is localized in nondesmosomal areas of the keratinocyte membrane, a localization also suggested for integrin ␣ 2 ␤ 1 (44).…”

Section: Discussionsupporting

confidence: 73%

Collagen XXIII, Novel Ligand for Integrin α2β1 in the Epidermis

Veit

Zwolanek

Eckes

et al. 2011

Journal of Biological Chemistry

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Cellular receptors for collagens belong to the family of ␤ 1 integrins. In the epidermis, integrin ␣ 2 ␤ 1 is the only collagenbinding integrin present. Its expression is restricted to basal keratinocytes with uniform distribution on the cell surface of those cells. Although ␣ 2 ␤ 1 receptors localized at the basal surface interact with basement membrane proteins collagen IV and laminin 111 and 332, no interaction partners have been reported for these integrin molecules at the lateral and apical membranes of basal keratinocytes. Solid phase binding and surface plasmon resonance spectroscopy demonstrate that collagen XXIII, a member of the transmembrane collagens, directly interacts with integrin ␣ 2 ␤ 1 in an ion-and conformation-dependent manner. The two proteins co-localize on the surface of basal keratinocytes. Furthermore, collagen XXIII is sufficient to induce adhesion and spreading of keratinocytes, a process that is significantly reduced in the absence of functional integrin ␣ 2 ␤ 1 .Collagen XXIII belongs to the class of transmembrane collagens in type II orientation, which comprises the collagens XIII, XVII, XXIII, and XXV and other related proteins such as ectodysplasin A, class A macrophage scavenger receptors, and the colmedins (1, 2). Collagen XXIII forms homotrimers consisting of a short intracellular domain, a single-pass transmembrane domain and three extracellular collagen domains interrupted by short noncollagenous sequences (3, 4). It exists either as a full-length, membrane-anchored protein or as a soluble ectodomain. The proteolytic processing releasing the ectodomain is mediated by furin and is regulated by the plasma membrane microenvironment (5). Collagen XXIII is expressed in the epidermis and other epithelia such as those in the tongue, gut, and lung but also in the brain and kidney (4). In prostate, collagen XXIII expression was shown to correlate with tumor progression (6).Four integrins, ␣ 1 ␤ 1 , ␣ 2 ␤ 1 , ␣ 10 ␤ 1 , and ␣ 11 ␤ 1 bind native collagens (7). This ␤ 1 subunit-containing subclass of integrins is characterized by the presence of an inserted domain (I domain) with homology to von Willebrand factor A domains in their ␣-subunit, which harbors the ligand-binding site (8, 9). The integrins ␣ 10 ␤ 1 and ␣ 11 ␤ 1 have a restricted expression pattern on differentiated chondrocytes and developing muscle cells (10, 11), whereas ␣ 1 ␤ 1 and ␣ 2 ␤ 1 show a broader distribution, with integrin ␣ 1 ␤ 1 being predominantly expressed by cells of mesenchymal origin and integrin ␣ 2 ␤ 1 by epithelial cells and platelets. In vitro studies suggested an implication of integrin ␣ 2 ␤ 1 in cell attachment and migration (12, 13), generation of mechanical forces and contraction of collagen matrices (14), induction of collagenase activity and matrix remodeling (15, 16), as well as angiogenesis (17) and epithelial branching morphogenesis (18). Mice lacking the integrin ␣ 2 subunit exhibit defects in mammary gland branching morphogenesis (19), delayed platelet aggregation and formation of unstable t...

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Section: Discussionsupporting

confidence: 73%

Collagen XXIII, Novel Ligand for Integrin α2β1 in the Epidermis

Veit

Zwolanek

Eckes

et al. 2011

Journal of Biological Chemistry

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“…In recent investigations we labeled many diVerent proteins using the method of SDS freeze-fracture cytochemistry (Peskan et al 2000;Galle et al 2002;Pop et al 2003;Sherameti et al 2004;Westermann and Rhiel 2005). We made the experience that white or bright appearing replica areas with thin or even no platinum deposition (platinum shadows) show equal or higher labeling eYciencies than regions consisting of mixed Pt/C.…”

Section: Resultsmentioning

confidence: 98%

Improved antigen retrieval in freeze-fracture cytochemistry by evaporation of carbon as first replication layer

Schlörmann

John

Steiniger

et al. 2007

Histochem Cell Biol

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The recently developed freeze-fracture replica immunolabeling technique uses sodium dodecyl sulfate to clean replicas obtained from chemically unfixed, rapidly frozen cells by evaporation of platinum as first and carbon as second replication layer. The detergent dissolves remains of cellular material with the exception of components which are in direct contact to the replica film. Membrane lipids and membrane protein complexes of the protoplasmic and the exoplasmic membrane halves remain attached to the replica film and are accessible for cytochemical localization. We immunolabeled the membrane proteins caveolin-1 and connexin 43 in mouse cell lines as well as the membrane attached protein tetrachloroethene reductive dehalogenase (PceA) in bacterial cells at freeze-fracture replicas generated by different evaporation parameters. The labeling experiments for caveolin-1 and the PceA showed that freeze-fracture replication of cellular membranes accomplished with thin platinum layers as well as replication with carbon as first evaporation layer lead in these cases to an improved antigen retrieval, whereas the labeling efficiency of connexin 43 was not affected by different evaporation conditions.

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“…Galle et al . () studied the contact zones of endothelial cells adhering to laminin‐coated surfaces. They found that RCM permitted the determination of the lateral position of the marked receptor molecules, to an accuracy of about 100–200 nm.…”

Section: Resolution Of Rcmmentioning

confidence: 99%

Applications of reflection‐contrast microscopy, including the sensitive detection of the results ofin situhybridisation a review

Ploem

2019

Journal of Microscopy

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Summary The observation with RCM of the reflection from reaction products produced by nonisotopic in situ hybridisation and a peroxidase staining, has recently facilitated the identification of single copy genes. RCM also reveals light microscope structures in stained ultrathin (0.1 μm) epon and lowicryl sections. In such preparations no out‐of‐focus blur can be observed. Confocal optics are thus not needed to obtain high‐quality images of ultrathin sections at the highest conventional light microscope optical resolution, and with higher image‐contrast than can be obtained by classical absorption microscopy. Such RCM images provide the same type of information as confocal scanning microscope images. A sequential ultrathin section of the same microscopic specimen can be examined with electron microscopy for a simple and accurate (CLEM) procedure. For some applications RCM can replace (CLSM). Lay Description With reflection contrast microscopy (RCM), a microscope image can be observed if micromirror‐like reflecting substances are present in the reaction product of cytochemical stains. Using an antiflex objective for RCM, the reflected incident light from the stained microscope specimen can be observed with only a small amount of unwanted stray‐light in the image background. Stray‐light is caused by reflection of incident light from the surface of the lenses in the microscope objective and in the microscope tube (using a 50% beam splitter for epi‐illumination). Several authors who compared RCM with bright‐field and fluorescence microscopy, found RCM to be a sensitive microscope method in many applications. It has been reported that RCM, using in situ hybridisation methods, can detect DNA sequences in single copy genes. In the literature is mentioned that single copy genes have an estimated mass of less than a trillionth of a gram of DNA. From stained ultrathin microscope sections with less than 0.1 μm thickness, multicoloured images with a high image contrast, optimal resolution and no out‐of‐focus blur can be observed with RCM. To achieve this, RCM uses an antiflex microscope objective, with a quarter‐wave plate mounted on the front lens in combination with a polarising filter cube inserted in the epi‐illuminator. RCM can also make use of oblique illumination, for a further increase of the image‐contrast and the resolution of the microscope image. A central stop has then to be inserted in the aperture plane of an epi‐illuminator.

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Local Cell Membrane Deformations due to Receptor-Ligand Bonding as Seen by Reflection Microscopy

Cited by 5 publications

References 42 publications

Collagen XXIII, Novel Ligand for Integrin α2β1 in the Epidermis

Collagen XXIII, Novel Ligand for Integrin α2β1 in the Epidermis

Improved antigen retrieval in freeze-fracture cytochemistry by evaporation of carbon as first replication layer

Applications of reflection‐contrast microscopy, including the sensitive detection of the results ofin situhybridisation a review

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